This trail runs along the route of two mining railways. The first, dating from 1874, linked the iron and coal mines of the Quirós Valley with Trubia Station, amounting to 30 km of tracks.

A branch line was incorporated into this route that, from Caranga de Abajo, linked with the Teverga mines, an additional 10 km that made up a Y-shaped route, whose construction and initial operation was undertaken by the Compañía de Minas y Fundiciones de Santander y Quirós. However, the truth is that shortly after, and until its closure,  it was exploited by Sociedad Anónima Fábrica de Mieres.

In any case, the railway project was much more ambitious, because it was intended to reach El Bierzo, but it never went beyond the Cantabrian divide.  Along the line, featuring tracks of the unusual width of 0.75 m, ran small locomotives and wagons full of ore that could barely face the steep ramps, putting their breaks to the test, rather than their engines, on the way done.

In the past, railways had to have brakemen on board the wagons, who obeyed the engineer’s orders to loosen or tighten the breaks in accordance with a code of whistles. Each brakeman was in charge of two wagons, moving from one to the other as necessary.  Built with maximum savings in mind, the tunnels of the line, 12 in total, were particularly narrow, frequently featuring rock overhangs above the track in sections running through ravines. And these stony peaks were to blame for the death of several brakemen who, passing from one wagon to another, were hit on the head by one of these rocks. Although the mines remained active until 1992, the train was closed and dismantled much earlier, in October 1963.